Production of cod-liver oil



Oct, 27, 1931. F. w. NITARDY PRODUCTION OF GOD LIVER OIL Filed March 30,1926 3 Sheets-Sheet l CONDENSER I STEAM LINE CENTRIFUGAL 2 INVENTOR E920M 0- Z;

I BY

ATTORNEYS 0d. 27, 1931. w, n- 1,829,571

PRODUCTION OF GOD LIVER OIL Filed Mafch 50, 1926 s Sheets-Sheet 2 SUPPL5m VACUUM TANK JETTLING TANKS CENTRIFUGAL INVENTOR ?&W 41-1 BY W 9 m; MAIM ATTORNEYS Oct. 27, 1931.

F. W. NITARDY PRODUCTION OF GOD LIVER OIL Filed March 30, 1926 3Sheets-Sheet 3 INVENTOR ATTORNEYS Patented Oct. 27, 1931 UNITED STATESPATENT OFFICE FERDINAND W. NITARDY, OF BROOKLYN, NEW YORK, ASSIGNOR TOE. R. SQUIBB AND SONS, OF NEW YORK, N. Y A CORPORATION OF NEW YORKPRODUCTION OF COD-LIVER OIL.

Application filed March 30, 1926.

This invention relates to the rendering of cod-liver oil andparticularly to a method of producing an improved cod-liver oil which isespecially adapted for medicinal use.

Cod-liver oil has been produced heretofore by cooking the whole liverswith steam. The oil separates in a layer above the solid materialresulting from the cooking operation when the mixture is permitted tocool and it can be withdrawn therefrom. The separation is not completeand much ofthe oil is lost. The oil recovered by the simple cookingoperation, if no special precautions are taken, is of relatively poorquality and is subject to rapid deterioration particularly with respectto. the development of a disagreeable odor and taste. It is usuallypermitted to contact with the atmosphere with the result that oxygen isabsorbed. The

oxygen attacks the vitamin content of the oil and reduces the amount ofthis important factor to a considerable extent. Much of the therapeuticvalue of the oil is thereby lost.

I have discovered, furthermore, that codliver oil absorbs or dissolves acertain amount of water and that the water contains albuminous materialwhich is derived from the livers. The absorbed water and the albuminousmaterial appear to have a deteriorating effect upon the oil so that themost carefully rendered oil develops an odorand taste if it is permittedto retain the normal moisture content. The oil, which when freshlyrendered is comparatively odorless and tasteless, becomes thusunsuitable or at least unsatisfactory for human consumption after arelatively short time.

It is the object of the present invention to provide a method ofrendering cod-liver oil which ensures maximum recovery of the oil andprotects it at the same time against deteriorating influences from thefirst separation of the oil to the ultimate packaging thereof,

Another object of the invention is to prevent deterioration of the oilby reason of the unavoidable presence of materials therein which'arederived from the livers and particularly to eliminate water from the oiland thus to provide a condition which favors the Serial No. 98,410.

indefinite preservation of the oil and the avoidance of the developmentof odor and taste therein.

Other objects and advantages of the invention will be apparent as it isbetter understood by reference to the following specification and theaccompanying drawings, in which Fig. 1 is a flow sheet indicating thepreferred arrangement of the apparatus employed in carrying out theinvention;

Fig. 2 is a plan view of a plant indicating the desirable arrangement ofthe apparatus;

Fig. 3 is a vertical section through one of the cookers;

Fig. 4 is a vertical section through a settling tank;

Fig. 5 is a sectional view chamber; and

Fig. 6 is a similar view of a trap in which water is separated from theoil before it is delivered to the drying chamber.

In order to produce cod-liver oil of high qualityit is essential tomaintain absolute cleanliness of the apparatus employed. The apparatushereinafter described is designed particularly to permit access to theinterior in order that it may be cleaned periodically and thusmaintained in a sanitary condition.

The livers which are generally delivered in barrels are carefullyselected. They are dumped from the barrels into a storage bin from whichthey flow to sorting tables. At the tables the operators sort the liversand free them from all foreign material. Any 85 diseased or unsoundlivers are withdrawn. The good livers are placed in suitable receptaclesand transferred to the washing appa ratus where they are subjected to athorou h washing to remove any adhering foreign su stances. When theyhave been washed the livers are ready for utilization in the process.

The livers are first chopped in a suitable apparatus provided for thatpurpose into relatively small pieces and these are transferred to thecooker. The latter is a jacketed kettle capable of holding, for example,about six barrels of the chopped livers and provided with a jacket and asteam coil through which steam may be passed to raise the temof thedrying I regulated. Too short a cooking perature of the contents. Thecoil is provided preferably with small orifices through which the steamcan be blown directly into the mass to be cooked. A suitable agitator islikewise provided so that the contents of the cooker can be stirredduring the operation.

The cooking of the livers must be closely eriod results in a failure tocompletely li rate the oil whereas extended cooking lowers the qualityof the oil. The total time required to cook a mass of livers containingabout six barrels of raw material with the apparatus hereinafterdescribed is about twenty-five minutes. As soon as the chopped liversare placed in the cooker the steam is turned on and passes through theorifices in the-coil directly into the mass. This raises the mass to theboiling point in approximately seven to eight minutes. Some-of the steamis condensed and additional water is derived from the livers so that asthe boiling proceeds the amount of water in the cooker increases. Assoon as the boiling temperature is reached the introduction of steam isregulated so as to 'maintain the boiling temperature and the operationis 'continued for approximately fi een to seventeen mlnutes. The mass isconstantly agitated during the boiling operof the oil, however, does notseparate and riseation by the mechanical agitator. A suitable agitatoris a propeller having a driving motor directly connected thereto. Suchan agitator canbe employed with a plurality of cookers. The cookingaccomplishes the coagulation of albuminous material which has a tendencyto emulsify the oil and permits the oil to be liberated quite completelyfrom the chum or waste material.

During the boiling the fat cells in the livers are broken down and theoil is released. All

to the surface of the mass. Consequently there is no danger of injury tothe oil by contact of the atmosphere therewith. Furthermore, the steamrising from the mass efl'ectually excludes air from the surface thereofand the oilis thus protected.

As soon as the cooking is completed the mass is transferred by means ofa sludge pump to a separating tank which is provided with heat insulatedwalls so. that the mass of material may remain therein for aconsiderable period without substantial reduction of the temperaturethereof. This avoids the necessity of heating the material in theseparating tank and ensures the maintenance of the mass at a temperatureabove 140 F. So long as this or a higher temperature is maintained thereis no tendency for putrefaction or fermentation of the mass. At lowertemperatures the, liver tissue is extremely sensitive and decomposesrapidly owing to the presence of bacteria and enzymes therein. Theavoidance of these undesirable reactions separating tank the latter isblown out with steam to remove all of the air therefrom and when thematerial has been introduced to the tank, steam is again blown over thesurface to remove any air which may be present and an inert gas such ascarbon dioxide is introduced to the space above the mass to ensure theabsence of air in the atmosphere above the oil which quickly separates..The mass settles into three layers, the oil being at the top andoverlyinga layer of cooked liver tissue. The bottom layer consists ofwater carrying some fragments of liver tissue. About one-third of thecontents of the tank will normallybe oil and this represents the greaterportion of the oil recovered from the livers. There is, however, acertain amount of oil trapped in the fragments of liver tissue.

At the end of about thirty minutes the overlying layer of oil iswithdrawn as hereinafter described and a screen is then introduced inthe tank above the level of the layer of liver tissue therein. Thescreen should be of relatively fine mesh adapted to prevent the passageof the fragments of liver tissue and it is firmly clamped in place bymeans provided for that purpose. Hot water is then introduced at thebottom of the tank in regulated quantity. The addition of water causesthe layer of liver tissue to rise until it strikes the screen and thecontinued introduction of hot water under pressure results'in thepassage of water through the liver tissue andthe separation therefrom ofthe oil which is mechanically held by the fragments. A considerableadditional recovery of oil is thus possible. The oil floats upon thewater and can be withdrawn and mixed with the oil recovered in the firstseparation.

Throughout the period of settling and the separation of the oil from thematerial in the settling tank a non-oxidizing atmosphere is maintainedin contact with the oil. The oil is removed by suction applied throughsuitable connections to a funnel having a screened inlet which permitsthe oil to pass from the tank. Some water may escape with ingdecomposition reactions with the resulting development of odor and tastein the oil. Furthermore, the dissolved water contains albuminous matterwhich likewise facilitates decomposition.

The removal ofthe water is accomplished by spraying the warm oil into achamber which is maintained under a suitable vacuum. The vacuum ordrying chamber is jacketed for steam or other heating media and isthereby maintained at a suitable temperature, for example, 150 F. As theoil is drawn through the spray head it is atomized and at thetemperature maintained the moisture content is evaporated and withdrawnfrom the chamber. The oil is separately collected and is delivered fromthe drying chamber to a filter press which serves to remove albuminousmaterial which coagulates upon the withdrawal of moisture from the oil.The removal of the albuminous material reduces the possibility ofsubsequent decomposition of the oil. Provision is made in the apparatusto permit the introduction of an inert gas such as carbon dioxide as maybe necessary to prevent the entrance of air and contact thereof with theoil and especially to permit flooding of the system with the inert gaswhen the operation is temporarily discontinued.

It is possible to employ other methods of drying the extracted oil. Thevacuum centrifugal method may be used. This method consists of runningthe oil through a centrifuge, the head 01' top of which is so inclosedin a chamber that it can be operated under vacuum. The oil fiows intothe bottom of a centrifuge basket which is of relatively small diameterand quite tall, and in traveling upward dispersed water is separatedfrom it as are also dispersed solids. The dispersed solids form a layerin the centrifuge bowl, whereas the water and oil flow upward in twoseparate layers from which the oil over flows. As the bowl is spinningat very high speed the overflowing oil is thrown out in the form of aspray, and as the head is kept under vacuum you really get the effect ofa spray dryer from this machine. The oil collects in the head and runsout by gravity. The use of such a centrifuge, of course, does noteliminate the necessity of a filter press, for some material iscoagulated by the evaporation of dissolved moisture, but much lessmaterial needs to be removed after running the oil through such acentrifuge than is the case when spray drying is used, because none ofthe solids, which usually represent fragments of liver tissue, areremoved in the spray drying process.

After the oil has been filtered it may be delivered to suitablecontainers. These may be evacuated before the oil is permitted to ienter or preferably they may be filled with an inert gas such as carbondioxide which is displaced by the oil. The oil is introduced to thereceptacles without contact with the air and a suflicient amount of theinert gas remains in the receptacles above the level of the oil thereinto prevent contact of the air and consequent destruction of the vitamincontent of the oil.

' The maintenance of the oil out of contact with the air throughout theseveral operations from the cooking of the livers to the final packagingof the oil is essential to the production of a high grade productcontaining the maximum vitamin content. Codliver oil has a markedafiinity for oxygen so that if a quantity thereof is shaken in a bottlecontaining air a partial vacuum will be created if the bottle is closedand an analysis of the gas above the oil will show that it is free fromoxygen. It is probable that while a brief exposure of the oil to theatmosphere has little immediate effect upon the vitamin content of theoil, the oxidation products which are readily formed in the cod-liveroil attack the vitamins and thus eventually cause deterioration of theoil. While the explanation noted is notnecessarily acorrect statement ofthe effect of oxygen, t is nevertheless true that the oil derived 'bythe process herein described is markedly superior to ordinary cod-liveroil in its vitamin content, its freedom from odor and taste and its lackof susceptibility to deteriorating influences.

The process and its application may be more readily understood byreference to the accompanying drawings, in which 5 indicates a suitableplatform upon which the barrels containing the livers are received. Thelivers are dumped into a bin 6 having a plurality of outlets 7 whichdischarge upon sorting tables 8. Each of these tables is in charge of anoperator who selects the livers to be used in the process and placesthem in barrels 9. The barrels are conveyed to a washing trough 10 wherethe livers are subjected to a thorough washing with Water. They are thendischarged upon a screen 11 which permits the draining of the watertherefrom and passed thence to a chopping machine 12. The latter may beof any suitable form and construction, the well known Enterprise powerchopper being adapted for the purpose. The chopped livers are deliveredinto receptacles 13 which may be lifted, for example, by a crane 1 1 topermit delivery of the material to one of the cookers 15.

The cooker is a vessel preferably cylindrical in form and having ajacket 16 of heatinsulating material such as ground cork. This preventsloss of heat during the cooking operation and permits greater economy inthe handling of the material. The cooker is adapted, moreover, for useas a settling tank when the other tanks of the system are filled withmaterial. A perforated pipe 17 is disposed in the bottom of the cookerand is connected by a pipe 18 to a source of steam under pressure. Thesteam can be delivered through the perforated pipe directly to thecontents of the cooker. An outlet 19 is provided in the bottom of thecooker and is controlled by a valve 20 having a stem 21 and an operatinghandle 22 adjacent the top of the cooker. A cover 23 having a dependingedge 24 is provided so that the cooker may be closed when it is used asa settling tank. The depending edge 24 rests in a water seal 25 whicheffectually prevents the entrance of air when the cover is in place. Arelief vent 26 is provided to permit escape of steam from the spaceabove the material in the cooker and connections 27 and 28 are providedfor the introduction of steam and an inert gas such as carbon dioxide.

When the material has been delivered to the cooker the steam is turnedon and permitted to flow through the perforated pipe into contact withthe material. The cooker is open at the top during this period of theoperation and an agitator having, for example, a propeller 28' driven bya motor 29 can be hung on the side of the cooker and operated to causethe proper mingling of the contents of the cooker. Steam is introducedactively until boiling commences and the introduction of steam isregulated thereafter until the cooking is completed Which should beapproximately twenty-five minutes after the commencement thereof in acooker of the capacity mentioned.

a As soon as the cooking is completed the mass is discharged through apipe 29 and a sludge pump 30 to a settling tank 31. The settling tank ispreferably cyllndrical in form and is provided with a jacket 32 filledwith heat-insulating material such as ground cork for the purpose ofpreventing loss of heat from the mass in the settling tank when the massis permitted to remain therein for a considerable period. The tank isprovided with a cover 33 having a depending edge 34 which is adapted tofit a water seal 35 at the top of the tank. Inlets 36 and 37 permittheintroduction of steam or of inert gas such asv carbon dioxide throughthe cover when the latter is inv place. A vent 38 permits the escape ofgas from the tank and prevents the building up of a pressure therein. Anoutlet 38'- is provided at the bottom of the tank and is closed by avalve39 having a stem 40 and an operating handle 41. A shoulder 42 isprovided within the tank to receive a screen 43 which may be held inplace on-the shoulder by any suitable clamping means.

As soon as the material has been delivered to the settling tank the oilcommences to rise to the surface. After a period of approximately thirtyminutes the major portion of the oil will have separated and the tworemaining layers in the tank will consist atthe bottom of watercontaining small particles of the liver tissue and a layer of livertissue above that and beneath the oil. The layer of oil is withdrawnthrough a funnel 43' which is connected to a hose 44 and is providedwith a screened inlet .to prevent the entrance of liver tissue.Substantially all of the oil on the surface of the mass is thusseparated and treated as hereinafter described. The screen 43 is theninserted and fitted in position above the layer of liver tissue, thesurface of which should be below the shoulder 42. Thereafter hot wateris introduced at the bottom of the tank through an inlet 45. The waterwhich is under a sllght pressure forces the layer of liver tissue torise against the screen. The hot water percolates through this layer andcarries with it'the oil which is mechanically held by, the particles ofliver tissue. The oil rises with the water above the screen but theliver tissue is retained thereby. This operation is continued for aperiod of hours so as to permit maximum recovery of the oil. Meanwhilethe mass is maintained at a temperature above 140 F. by the surroundinginsulation or is otherwise heated so as to prevent a reduction in thetemperature to a point where putrefaction may occur. The layer of oil iswithdrawn through the funnel 43 and mixed with the oil first separated.The balance of the material in the settling tank is then discharged andtreated as hereinafter described.

The oil passes through a pipe 46 which is connected with the hose 44 andinto a Water separator 47. Any water which passes over with the oil fromthe settling tank drops to the bottom of the separator and the oil iswithdrawn from the top thereof and is delivered through a pipe 48 to adrying chamber 49. The pipe 48 terminates in a nozzle 50 in the dryingchamber.

The drying chamber is preferably cylindrical in form and is providedwith a jacket 51: through which steam or hot water may be circulated tomaintain the required temperature therein. The warm oil entering throughthe pipe 48 is discharged through the nozzle 50 into the chamber in theform of fine oil particles. The exposure of these particles at thetemperature maintained results in the vaporization of the moisturecontent of the oil. The vapor is withdrawn through an outlet 52 which isconnected to a suitable vacuum pump. Abaflie 53 prevents the passage ofoil particles into the outlet. The oil accumulates in the bottom of thechamber and a gauge 54 is provided to indicate the amount of oilthereincontained. The accumulated oil is withdrawn through an outlet 55at the bottom of the chamber which connects through a pipe 56 to a puinp57 which forces the oil through a filter press The filter press 58 ofthe ordinary type. separates coagulated albuminous material and anyother solid material which may remain in the oil. The clear oil isdelivered through a pipe 59 to a receptacle 60 which is adapted for thetransportation and storage of the oil. Preferably the receptacle isflushed with an inert gas such as carbon dioxide before it is connectedto the filter press, the inert gas being displaced as the receptacle isfilled.

A. container 61 for an inert gas, for example, carbon dioxide underpressure is connected to the pipe 56'so that the inert gas can bedelivered to the drying chamber, to the filter press and elsewherethrough the system either to maintain a non-oxidizing atmosphere incontact with the product during the operation or to force air from thesystem. The pressure equalizer may conveniently be a flexible gas-tightbag Which expands and contracts according to the pressure in the gasline, so that the surges and pressure variations of the gas will beabsorbed and a substantially steady flow of gas produced. It is animportant feature of the invention that air is prevented from coming incontact with the oil through-out the operation from the cooking of thelivers to the final packaging of the product. In the cooking operationit is not necessary to use an inert gas because of the presence of steamabove the mass. Thereafter tne inert gas is introduced wherever there isa possibility of the presence otherwise of oxygen in contact with theoil; A pipe 62 is connected to the vapor outlet line 52 of the dryingchamber and to a coil 63 which is disposed in a suitable receptacle 64adapted to be supplied with cooling water. The coil causes thecondensation of the moisture recovered from the oil and this can bedischarged through an outlet pipe 65 to the sewer or elsewhere. A vacuumpipe 66 which may be connected to anysuitable exhausting device forms abranch of the pipe 65 and maintains the necessary reduced pressure inthe drying chamber;

The liver tissue from the settling tank still contains some oil afterthe second separation thereof. It is delivered consequently to acentrifugal 67 of the usual type in which a large proportion of thewater and oil present is separated by centrifugal force. The oil, beingthereby subjected to a certain amount of contact with the atmosphere, isinferior to the oil recovered by skimming from the settling tank. Theoil is therefore separated from the water and sold as No. 2,0il. Theremaining solid material may be removed from the centrifugal and treatedfurther for the production of desired by-products. A further amount ofoil may be obtained, for example, by pressing, or the mass maybe driedunder vacuum for the purpose of obtaining anhydrous liver tissue whichwill consist approximately of 50% protein and from 30 to 35% of fat, thebalance being fibre, mineral matter, etc. This material is suitable forvarious uses such as the production of cattle feed and fertilizers inwhich the nitrogenous content of the material is valua le.

It is to be understood that in the operation of the plant as described aplurality of cookers are preferably employed and a sufficient number ofsettling tanks are provided to permit the handling of the product of thecookers. The settling tanks and cookers are conveniently arranged tofacilitate the handling of the material and particularly the dischargeof the solid materials to the centrifugal. Since it may be necessary attimes to hold the cooked product in the cookers the latter are designedas settling tanks and the operations described with respect to thesettling and removal of the oil may be conducted in the cookers. Infact, the settling tanks can be omitted and the operation can beconducted up to the point of discharging the solid material to thecentrifugal solely in the cooker. In this case the cooker will remainopen during the cooking operation since the steam excludes air and thecover provided for the purpose will be applied before settling commencesso that all of the air can be evacuated from the cooker and contact ofoxygen with the oil prevented thereby.

The dehydration of the oil results in a marked improvement in thequality thereof, particularly with respect to the inhibiting of thedevelopment of odor and taste therein. Since the development 'of odorand taste is apparently the result of decomposition of some constituentof the oil, it is apparent that the removal of the water results eitherin the removal of this constituent or produces a, condition in whichdecomposition is no lon er possible. It is quite probable that theimproved quality of the 011 results from the separation of albuminousmatter which, as hereinbefore noted, coagulates when the oil isdehydrated. I have discovered, however, that the presence of odor andtaste in the oil can be inhibited also by the addition of a suitablesalt to the livers during the cooking operation or subsequently to theoil. Common salt (sodium chloride) is well adapted for this use. From 5to 10% of common salt can be added to the livers when they are cooked.The presence of salt in the liquor with which the oil is in contact hasthe eifect apparently of wholly or partially dehydrating the oil.Because of the limited amount of water in the separated oil as little asone-half pound of common salt per barrel of oil will secure the desiredresult. The albuminous matter which is detectable in the oil only whenit contains absorbed water is prevented apparently from entering the oilwhen it is in contact with the saline solution or is preserved by thesalt. Consequently an oil of improved quality is recovered when salt isadded.

Whether or not a salt is added I prefer to dehydrate the'oil in thedrying chamber as hereinbefore indicated. The two operations can becombined with advantage to produce an oil of the highest quality which,ifstored and transported out of contact with the atmosphere, will retainits valuable vitamin content at substantially the initial stren h andwill remain free from disagreeable 0 or and taste for an indefiniteperiod. I am enabled thereby to produce an' improved and valuablecod-liver oil product by the application of the principles hereinbeforedescribed.

Various changes may be made in the details of the operation as describedand in. the construction and arrangement of the apparatus employedtherein without departing from the invention or sacrificing anypf theadvantages thereof.

I claim In the process of producing a medicinal cod liver oil, the stepof atomizing the oil and simultaneously heating it under reducedpressure to remove moisture therefrom, filtering the heated oil toremove solid impurities therefrom, and delivering the filtered oil tostorage receptacles, all of the said steps being carried out in theabsence of air and in the presence of an inert as.

In testimony whereof I a m si FERDINAND W. NIX

ature. DY.

